Last year, two of Denver's top restaurateurs picked up underground spots in Larimer Square, opening unique concepts right at the edge of LoDo. The first was Green Russell, a faux speakeasy fronted with a pie shop that Frank Bonanno opened last fall in an homage to the secret, pre-Prohibition-style cocktail bars emerging in bigger cities -- even if his version was never actually a secret. The second was Troy Guard and Leigh Sullivan-Guard's TAG | RAW BAR, a brightly lit annex of the original TAG that made its debut in March.

I've reviewed both of those places within the past month. And while TAG | RAW BAR was a successful concept from the start, Green Russell is still struggling to deliver on its promise. Here's why:

Green Russell tried to do too much.

Restaurants flourish when they have a clear vision for what they want to be -- and they keep that vision simple. Green Russell is a pre-Prohibition cocktail bar, and that's a great concept. So why deviate from it with a complicated drink list -- full of cocktails made with house-crafted tinctures and house-made horchata and herbs from the grow room -- when a couple of bartenders can't even make a proper Manhattan?

I'd be happier if I knew I could soak up the richly appointed atmosphere of Green Russell while nursing a kick-ass classic gin martini or well-made Sazerac at the end of a night, because that's what I expect from a pre-Prohibition cocktail bar. But that's not what you get at Green Russell.

And why muddy up the concept with mediocre food? Really, why serve food at all, beyond a couple of super-simple bar snacks? Green Russell's atmosphere should be satisfying enough.

TAG | RAW BAR better manages expectations by being completely unexpected.
The reason it's so important to have a clear vision for a restaurant is because pleasing customers ultimately comes down to managing expectations (this is why you have different standards for a fine-dining dinner and a jaunt to your local hole-in-the-wall). There are two ways to do that successfully. The first is to over-deliver on what you promise. The second is to completely upend diners' expectations from the outset and blow them away anyway.

Green Russell is taking the first path. A faux speakeasy may have been conceptually new to Denver, but it's not hard for most people to imagine a drinking den with an air of sultry secrecy plugged into a basement space. But add to that Bonanno's (deserved) reputation and the direct comparisons to some of the most formidable cocktail bars in the country, and suddenly you've set a pretty high bar for your bar -- and, unfortunately, left a lot of room for error.

TAG | RAW BAR, on the other hand, succeeds by delivering the totally unexpected. Instead of a cavernous, low-lit basement spot, it's awash with bright light and loud, poppy music. And even diners with a notion of what they might find at a raw bar likely won't expect the playful menu here, with sorbets, sauces and microgreens adding new dimension to an already unfamiliar concept. There's raw kangaroo on the menu, for God's sake. Yet it's all excellently executed, and each surprising find leaves you hungry for more.

TAG | RAW BAR feels much more adaptable.
There's having a clear conceptual vision, and then there's locking yourself into details that might be flawed. The Guards knew what they were creating, but they also expected to make changes as they went along. And so the menu has rotated, the specials change constantly and the chefs continue to ask for feedback and tweak dishes. That makes flaws (which are rare) forgivable. It's a work in progress, and the diner is invited to join in the process.

Green Russell, on the other hand, touted its dialed-in program as it was still building out the space, and all signs said it would be perfect from day one. But when it wasn't perfect, there should have been adjustments -- fast. Instead, it took several months to ditch the terrible French-bread pizzas. Another sign of inflexibility: a bartender explaining to me why my drink tasted the way it did but not fixing it. Yet another: The bar stocks only one vodka and charges $13 for a vodka tonic, since $13 is what it charges for every other drink on the menu.

I haven't ordered a vodka tonic since I was drinking on a fake ID, but that's ridiculous.

Six months after it opened, changes are in the works at Green Russell, with chef Sean Kelly lending a hand in the kitchen. So while it might be underground, things are looking up.